Answer:
C)
Step-by-step explanation:
Given:
s=3a
t=s+a
t=516
now lets use 3a instead of s.
516=3a+a
516=4a
a=129 (adult)
s=3(129)
s=387 (student)
median= 73
I was having trouble submitting a text answer, so I attached a file. Hope it helps.